Superoxide dismutase: a key target for the neuroprotective effects of curcumin

Over the past few years, the prevalence of neurodegenerative diseases (NDD) has increased dramatically. The community health system is burdened by the high healthcare costs associated with NDD. Superoxide dismutase (SOD) is a type of metalloenzyme that possesses a distinct characteristic of protecting the body from oxidative stress through antioxidants. In this way, SOD supplementation may activate the endogenous antioxidant mechanism in various pathological conditions and could be used to neutralize free radical excess. Several factors are responsible for damaging DNA and RNA in the body, including the overproduction of reactive species, particularly reactive oxygen species (ROS) and reactive nitrogen species (RNS). Excessive ROS/RNS have deleterious effects on mitochondria and their metabolic processes, mainly through increased mitochondrial proteins, lipids and DNA oxidation. Studies have shown that oxidative stress is implicated in the etiology of many diseases, including NDD. It is thought that anti-inflammatory compounds, particularly phytochemicals, can interfere with these pathways and regulate inflammation. Extensive experimental and clinical research has proven that curcumin (Cur) has anti-inflammatory and anti-neurologic properties. In this review, we have compiled the available data on Cur's anti-inflammatory properties, paying special attention to its therapeutic impact on NDD through SOD.

Gold nanoparticles (AuNPs) decrease the viability of cervical cancer cells by inducing the BAX gene and activating antioxidant enzymes

BACKGROUND

Cervical Cancer (CC), a leading cause of female mortality worldwide, demonstrates a direct association with high-risk human papillomavirus (HPV) infections. However, not all CC patients exhibit HPV infection, suggesting additional predisposing factors. Recently, disturbances in the oxidant-antioxidant balance have been implicated in CC development. This study explores the impact of gold nanoparticles (AuNPs) on the survival and antioxidant capacity of HeLa cells, aiming to contribute to novel CC therapy approaches.

METHODS AND RESULTS

Synthesized and characterized AuNPs (25.5 nm, uniform distribution according to the DLS analysis) were administered to HeLa cells at varying concentrations. After 24 h, cell viability was assessed using the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2 H-tetrazolium bromide) (MTT) assay. Real-time PCR measured expression levels of apoptosis-related genes (BCL2 associated X (BAX) and p53). Catalase and superoxide dismutase (SOD) activities, key antioxidant enzymes, were also evaluated post-AuNP treatment. AuNPs dose-dependently reduced HeLa cell viability, with an IC50 value of 113 µg/ml. BAX gene expression significantly increased, indicating pro-apoptotic effects. Moreover, enzyme activities significantly rose under AuNP influence.

CONCLUSIONS

AuNPs demonstrated the potential to induce HeLa cell death by upregulating pro-apoptotic BAX gene expression and altering antioxidant system enzyme activities. These findings underscore the promise of AuNPs as a therapeutic avenue for CC, emphasizing their impact on crucial cellular processes involved in cancer progression.

Association of serum superoxide dismutase activity and the incidence of colorectal cancer in a nested case-control study

BACKGROUND

Superoxide dismutase (SOD) is an antioxidant enzyme that degrades superoxide, a major causative factor in carcinogenesis. We assessed associations between serum SOD activities and incidence of colorectal carcinoma (CRC) in a case-control study nested in the Japan Collaborative Cohort (JACC) study.

METHODS

At baseline, 39,242 subjects donated serum samples. Participants diagnosed with CRC during follow-up were regarded as cases. Odds ratios (ORs) for CRC incidence associated with SOD were evaluated with conditional logistic regression models. In the current study, 176 cases and 524 controls were analyzed.

RESULTS

For the overall cohort, a decreasing trend in risk of CRC with increasing SOD was observed (P for trend=0.054) and the fourth quartile of SOD level showed the lowest risk compared to the first (OR=0.52, 95% confidence interval [CI]=0.29-0.93). This was significant in men (P for trend=0.001), with the fourth quartile of SOD level showing the lowest risk compared to the first (OR, 0.23; 95%CI, 0.09-0.60). It was also exclusively observed for rectal cancer and left-sided CRC (P for trend, 0.037 and 0.020, respectively), with the fourth quartile again showing the lowest risk compared to the first (OR, 0.28 and 0.38; 95%CI, 0.09-0.84 and 0.16-0.91, respectively). Limiting subjects to those followed-up over 2 years, all trends remained unchanged.

CONCLUSIONS

Our findings suggest that serum SOD activity correlates inversely with risk of CRC, particularly in men and individuals with rectal cancer/left-sided CRC.

Enzymatic response and antibiotic resistance gene regulation by microbial fuel cells to resist sulfamethoxazole

Microbial fuel cells (MFCs) are a promising and sustainable technology which can generate electricity and treat antibiotic wastewater simultaneously. However, the antibiotic resistance genes (ARGs) induced by antibiotics in MFCs increase risks to ecosystems and human health. In this study, the activities of enzymes and regulation genes related to ARGs in MFCs spiked with sulfamethoxazole (SMX) were evaluated to explore the induction mechanism of ARGs. Under lower doses of SMX (10 mg/L and 20 mg/L SMX in this study), microorganisms tend to up regulate catalase and RpoS regulon to induce sul1, sul3 and intI1. The microorganisms exposed to higher doses of SMX (30 mg/L and 40 mg/L SMX in this study) tend to up regulate superoxide dismutase and SOS response to generate sul2 and sulA. Moreover, the exposure concentrations of SMX had no significant effect on the electricity production of MFCs. This work suggested that the ARGs in MFCs might be inhibited by affecting enzymatic activities and regulatory genes according to the antibiotic concentration without affecting the electricity production.

In vivo antioxidant activity of rabbiteye blueberry (Vaccinium ashei cv. 'Brightwell') anthocyanin extracts

Blueberries are rich in phenolic compounds including anthocyanins which are closely related to biological health functions. The purpose of this study was to investigate the antioxidant activity of blueberry anthocyanins extracted from 'Brightwell' rabbiteye blueberries in mice. After one week of adaptation, C57BL/6J healthy male mice were divided into different groups that were administered with 100, 400, or 800 mg/kg blueberry anthocyanin extract (BAE), and sacrificed at different time points (0.1, 0.5, 1, 2, 4, 8, or 12 h). The plasma, eyeball, intestine, liver, and adipose tissues were collected to compare their antioxidant activity, including total antioxidant capacity (T-AOC), superoxide dismutase (SOD) activity and glutathione-peroxidase (GSH-PX/GPX) content, and the oxidative stress marker malondialdehyde (MDA) level. The results showed that blueberry anthocyanins had positive concentration-dependent antioxidant activity in vivo. The greater the concentration of BAE, the higher the T-AOC value, but the lower the MDA level. The enzyme activity of SOD, the content of GSH-PX, and messenger RNA (mRNA) levels of Cu,Zn-SOD, Mn-SOD, and GPX all confirmed that BAE played an antioxidant role after digestion in mice by improving their antioxidant defense. The in vivo antioxidant activity of BAE indicated that blueberry anthocyanins could be developed into functional foods or nutraceuticals with the aim of preventing or treating oxidative stress-related diseases.

The Interaction Effect of Sleep Deprivation and Treadmill Exercise in Various Durations on Spatial Memory with Respect to the Oxidative Status of Rats

Sleep deprivation (SD) has deleterious effects on cognitive functions including learning and memory. However, some studies have shown that SD can improve cognitive functions. Interestingly, treadmill exercise has both impairment and improvement effects on memory function. In this study, we aimed to investigate the effect of SD for 4 (short-term) and 24 (long-term) hours, and two protocols of treadmill exercise (mild short-term and moderate long-term) on spatial memory performance, and oxidative and antioxidant markers in the serum of rats. Morris Water Maze apparatus was used to assess spatial memory performance. Also, SD was done using gentle handling method. In addition, the serum level of catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GSH-Px) was measured. The results showed that 24 h SD (but not 4 h) had negative effect on spatial memory performance, decreased SOD, CAT, and GSH-Px level, and increased MDA level. Long-term moderate (but not short-term mild) treadmill exercise had also negative effect on spatial memory performance, decreased SOD, CAT, and GSH-Px level, and increased MDA level. Interestingly, both protocols of treadmill exercise reversed spatial memory impairment and oxidative stress induced by 24 h SD. In conclusion, it seems that SD and treadmill exercise interact with each other, and moderate long-term exercise can reverse the negative effects of long-term SD on memory and oxidative status; although, it disrupted memory function and increased oxidative stress by itself.

Field validated biomarker (ValidBIO) based assessment of impacts of various pollutants in water

The sensitivity of fish towards pollutants serves as an excellent tool for the analysis of water pollution. The effluents generated from various anthropogenic activities may contain heavy metals, pesticides, microplastics, and persistent organic pollutants (POPs) and ultimately find its way to aquatic environment. The enzymatic activities of fish collected from water bodies near major cities, oil spillage sites, agricultural land, and intensively industrialized areas have been reported to be significantly impacted in various field studies. These significant alterations in enzymatic activities act as a biomarker for monitoring purposes. The use of biomarkers not only helps in the identification of known and unknown pollutants and their detrimental health impacts, but also identifies the interaction between pollutants and organisms. The conventional method majorly used is physicochemical analysis, which is recognized as the backbone of the system for monitoring water quality. In physicochemical monitoring, major problems exist in assessing or predicting biological effects from chemical or physical data. Xenobiotic-induced enzymatic changes in fish may serve as an intuitive and efficient biomarker for determining contaminants in water bodies. Therefore, field validated biomarker (ValidBIO) approach needs to be integrated in water quality monitoring program for environmental health risk assessment of aquatic life impacted due to various point and non-point sources of water pollution.

Mixotrophic cultivation of Chlorella pyrenoidosa under sulfadiazine stress: High-value product recovery and toxicity tolerance evaluation

Sulfadiazine (SDZ) as a common sulfonamide antibiotic is frequently detected in wastewater, but there is little information on the high-value product recovery and toxicity tolerance evaluation of mixotrophic microalgae under SDZ stress. In this study, effects of SDZ on growth, photosynthesis, cellular damage, antioxidant capacity and intracellular biochemical components of Chlorella pyrenoidosa were investigated. Results showed that the growth of C. pyrenoidosa was inhibited by about 20% under high SDZ stress, but there was little impact on photosynthesis. Cellular damage and antioxidant capacity were evaluated using malondialdehyde (MDA) content and superoxide dismutase (SOD) activity to further explain the toxicity tolerance of mixotrophic microalgae. The SDZ stress not only increased lipid and carbohydrate content, respectively attaining to the maximum of 390.0 and 65.4 mg/L, but also improved the biodiesel quality of C. pyrenoidosa. The findings show the potential of mixotrophic microalgae for biodiesel production and wastewater treatment.

Genome-wide identification of the rubber tree superoxide dismutase (SOD) gene family and analysis of its expression under abiotic stress

Background

The rubber tree (Hevea brasiliensis) is the only species capable of producing high-quality natural rubber for commercial use, and is often subjected to various abiotic stresses in non-traditional rubber plantation areas. Superoxide dismutase (SOD) is a vital metalloenzyme translated by a SOD gene family member and acts as a first-line of protection in plant cells by catalysing the disproportionation of reactive oxygen species (ROS) to produce H₂O₂ and O₂. However, the SOD gene family is not reported in rubber trees.

Methods

Here, we used hidden markov model (HMM) and BLASTP methods to identify SOD genes in the H. brasiliensis genome. Phylogenetic tree, conserved motifs, gene structures, cis elements, and gene ontology annotation (GO) analyses were performed using MEGA 6.0, MEME, TBtools, PlantCARE, and eggNOG database, respectively. HbSOD gene expression profiles were analysed using quantitative reverse transcription polymerase chain reaction (qRT-PCR).

Results

We identified nine HbSOD genes in the rubber tree genome, including five HbCSDs, two HbFSDs, and two HbMSDs. Phylogenetic relationship analysis classified the SOD proteins from the rubber tree and other related species into three subfamilies. The results of gene structure and conserved motif analysis illustrated that most HbSOD genes have similar exon-intron numbers and conserved motifs in the same evolutionary branch. Five hormone-related, four stress-related, and light-responsive elements were detected in the HbSODs' promoters. HbSODs were expressed in different tissues, gradually increased with leaf development, and were abundantly expressed in mature leaves. HbCSD2 and HbCSD4 was significantly upregulated under low and high temperatures, and salt stress, except for HbCSD2, by heat. Furthermore, most HbSOD genes were significantly upregulated by drought, except HbMSD2. These findings imply that these genes may play vital roles in rubber tree stress resistance. Our results provide a basis for further studies on the functions of HbSOD genes in rubber trees and stress response mechanisms.

Insights to the superoxide dismutase genes and its roles in Hevea brasiliensis under abiotic stress

The superoxide dismutase (SOD) protein significantly influences the development and growth of plants and their reaction to abiotic stresses. However, little is known about the characteristics of rubber tree SOD genes and their expression changes under abiotic stresses. The present study recognized 11 SOD genes in the rubber tree genome, including 7 Cu/ZnSODs, 2 MnSODs, and 2 FeSODs. Except for HbFSD1, SODs were scattered on five chromosomes. The phylogenetic analysis of SOD proteins in rubber trees and a few other plants demonstrated that the SOD proteins contained three major subgroups. Moreover, the genes belonging to the same clade contained similar gene structures, which confirmed their classification further. The extension of the SOD gene family in the rubber tree was mainly induced by the segmental duplication events. The cis-acting components analysis showed that HbSODs were utilized in many biological procedures. The transcriptomics data indicated that the phosphorylation of the C-terminal domain of RNA polymerase II might control the cold response genes through the CBF pathway and activate the SOD system to respond to cold stress. The qRT-PCR results showed that the expression of HbCSD1 was significantly downregulated under drought and salt stresses, which might dominate the adaption capability to different stresses. Additionally, salt promoted the expression levels of HbMSD1 and HbMSD2, exhibiting their indispensable role in the salinity reaction. The study results will provide a theoretical basis for deep research on HbSODs in rubber trees.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03328-7.

The effect of Crocin on TFAM and PGC-1α expression and Catalase and Superoxide dismutase activities following cholestasis-induced neuroinflammation in the striatum of male Wistar rats

Bile secretion is a physiological function that is disrupted following Bile Duct Ligation (BDL) and induces cholestasis. Cholestasis is a bile flow reduction that induces apoptosis, oxidative stress, and inflammation, and alters the expression of genes. Evidence shows the relationship between cholestasis and neuroinflammation. Cholestasis via attenuating mitochondrial biogenesis and anti-oxidant activity can induce neuroinflammation and apoptosis. Mitochondrial transcriptional factor A (TFAM) and Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) are involved in mitochondrial biogenesis, and TFAM, PGC-1α, Catalase (CAT), and Superoxide dismutase (SOD) have a role in upregulating antioxidant pathways. On the other hand, many studies have shown the neuroprotective effects of Crocin, the water-soluble carotenoid of Saffron (Crocus sativus L.). In this study, we aimed to investigate the effect of Crocin on the level of TFAM, PGC-1α, CAT, and SOD following cholestasis-induced neuroinflammation in the rat's striatum. Cholestasis was induced by BDL surgery and administration of Crocin was intraperitoneal, at the dose of 30 mg/kg every day, 24 h after BDL surgery up to thirty days. The results showed that TFAM, PGC-1α, and SOD were decreased following cholestasis; while, CAT was increased. In addition, Crocin restored the effects of cholestasis on the level of TFAM, PGC-1α, and SOD. In conclusion, Crocin may have improvement effects on cholestasis-induced neuroinflammation in the rat's striatum.

Enzymatic response to cadmium by Impatiens glandulifera: A preliminary investigation

This paper aims to develop our understanding of the effect of cadmium (Cd) on Impatiens glandulifera, a recently identified potential Cd hyperaccumulator. Impatiens glandulifera plants were exposed to three concentrations of Cd (20, 60 and 90 mg/kg) and were sampled at two timepoints (one and seven days) to investigate the stress response of I. glandulifera to Cd. Cd can induce oxidative stress in plants, triggering overproduction of reactive oxygen species (ROS). The level of activity of catalase (CAT) and ascorbate peroxidase (APX), two crucial antioxidant enzymes responsible for detoxifying ROS, were found to increase in a concentration dependent manner. Though there was no change observed in the level of superoxide dismutase (SOD) activity, the activity of glutathione S-transferase (GST), involved in detoxifying and sequestering Cd, increased after exposure to Cd. Cd did not appear to impact the levels of proline and photosynthetic pigments, indicating the plants weren't stressed by the presence of Cd. These results suggest that the rapid response observed in enzyme activity aid the efficacious mitigation of the toxic effects of Cd, preventing significant physiological stress in I. glandulifera.

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Impatiens glandulifera display an enhance tolerance to Cadmium.

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An early response in a Catalase and Peroxidase ascorbate mediates Cadmium tolerance.

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No impact on stress indicators were shown by Impatiens glandulifera even after 7 days.

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SOD was found to be not involved in the early response to Cadmium.

Exposure of the alga Pseudokirchneriella subcapitata to environmentally relevant concentrations of the herbicide metolachlor: Impact on the redox homeostasis

This study investigated the effect of the herbicide metolachlor (MET) on the redox homeostasis of the freshwater green alga Pseudokirchneriella subcapitata. At low MET concentrations (≤40 μg L^-1), no effects on algal cells were detected. The exposure of P. subcapitata to 45-235 μg L^-1 MET induced a significant increase of reactive oxygen species (ROS). The intracellular levels of ROS were particularly increased at high (115 and 235 μg L^-1) but environmentally relevant MET concentrations. The exposure of algal cells to 115 and 235 μg L^-1 MET originated a decrease in the levels of antioxidants molecules (reduced glutathione and carotenoids) as well as a reduction of the activity of scavenging enzymes (superoxide dismutase and catalase). These results suggest that antioxidant (non-enzymatic and enzymatic) defenses were affected by the excess of MET. As consequence of this imbalance (ROS overproduction and decline of the antioxidant system), ROS inflicted oxidative injury with lipid peroxidation and damage of cell membrane integrity. The results provide further insights about the toxic modes of action of MET on a non-target organism and emphasize the relevance of toxicological studies in the assessment of the impact of herbicides in freshwater environments.

The toxicity of virgin and UV-aged PVC microplastics on the growth of freshwater algae Chlamydomonas reinhardtii

Although more attention has been paid to plastic pollution in marine ecosystems, research on the influence of plastic in freshwater ecosystems remains limited. To help fill this information gap, this article represents an investigation of the effects of virgin polyvinyl chloride (v-PVC) microplastics (MPs) and UV-aged polyvinyl chloride (a-PVC) MPs on the growth and chlorophyll content of the freshwater algae, Chlamydomonas reinhardtii (C. reinhardtii) at different periods (0, 24, 48, 72 and 96 h). The results suggest that both virgin and aged PVC MPs have negative effects on the growth of C. reinhardtii in the range of 10 mg/L to 200 mg/L, which leads to the reduction of chlorophyll-a level in the cells. Furthermore, a-PVC MPs were more toxic than v-PVC MPs, as shown by the a-PVC MPs' lower EC₅₀ values after 96 h (63.66 mg/L for a-PVC MPs and 104.93 mg/L for v-PVC MPs). The inhibition effect of both kinds of PVC was also testified by the enhancement of enzymatic activity of superoxide dismutase (SOD) and malondialdehyde (MDA) in algae. Meanwhile, a-PVC MPs obviously had a higher toxicity than v-PVC MPs. The aging process that affected the surface characteristics of a-PVC was identified using Fourier transform infrared (FTIR) and Zetasizer. The carbonyl groups formed on the surface and the increased zeta potential of the a-PVC MPs affected the interaction between the microplastics and the algae, which increased the toxicity of aged microplastics. The research results presented here provide more evidence of the risks microplastics bring into the freshwater ecosystem.

Inactivation effect and mechanisms of combined ultraviolet and metal-doped nano-TiO2 on treating Escherichia coli and Enterococci in ballast water

The discharge of ship ballast water (containing large amounts of alien organisms) has caused severe ecological hazards to marine environments. In this study, three metal elements (Ag, Fe, and Gd) were doped to nano-TiO₂ material respectively (content: 0.4%, 0.7%, and 1.0%) to improve inactivation effect of Escherichia coli and Enterococci in ballast water. Experimental results indicate that compared with the sole ultraviolet (UV) and the UV and original nano-TiO₂, the UV and metal-doped nano-TiO₂ increased the bacterial inactivation rate to different extents. For each metal element, high external metal content (1.0%) corresponded to high inactivation effort. The doping of Ag resulted in optimal inactivation effort, and the addition of Fe and Gd caused unobvious effort. At the end of the inactivation process (20 s), the UV and 1% Ag-doped nano-TiO₂ reached the highest logarithmic sterilization rates (0.915 for Escherichia coli and 0.805 for Enterococcus). The doping of Ag, Fe, and Gd did not change the anatase phase TiO₂ crystal form, and 1% Ag-doped nano-TiO₂ had the smallest particle diameter and the evenest distribution of nanoparticles. Compared with the sole UV, the UV and Ag-doped nano-TiO₂ treatment resulted in higher malondialdehyde contents (0.0646 μmol/L for Escherichia coli and 0.0529 μmol/L for Enterococci) and lower superoxide dismutase activities (0.672 U/mL for Escherichia coli and 0.792 U/mL for Enterococci), which were in accordance with high inactivation rates in these cases.

Effect of APTES modified TiO2 on antioxidant enzymes activity secreted by Escherichia coli and Staphylococcus epidermidis

In this work, the impact of APTES-modified TiO₂ photocatalysts on antioxidant enzymes (catalase and superoxide dismutase) activity secreted by bacteria was presented. Microbial tests has been examined using Escherichia coli (ATCC 29425) and Staphylococcus epidermidis (ATCC 49461) as model organisms. It was found that APTES-TiO₂ affected the activity of antioxidant enzymes. Additionally, obtained APTES-TiO₂ photocatalysts were capable of total E. coli and S. epidermidis inactivation under artificial solar light irradiation. The sample modified with the concentration of APTES equals 300 mM (TiO₂-4h-120°C-300mM) showed the strongest photocatalytic activity toward both bacteria species. The two-stage photocatalytic mechanism of bacteria response to photocatalysts was proposed.

Effect of phenanthrene on the biological characteristics of earthworm casts and their relationships with digestive and anti-oxidative systems

Earthworms as ecosystem engineers partially improve soil properties by egesting casts. Our previous study confirmed that soil pollution affects the physico-chemical properties of earthworm casts. It is still unclear whether the biological properties (e.g. cellulase, urease, and acid and alkaline phosphatase activities, as well as microbial biomass carbon) of casts are affected by foreign substances in soil. The present study aimed to investigate the effect of phenanthrene (PHE) on the biological characteristics of earthworm (Eisenia fetida) casts. Furthermore, correlations between cast properties and the digestive and antioxidant systems were explored by the determination of digestive enzyme (urease, protease, acid and alkaline phosphatase) activities, antioxidant indexes [superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD)], as well as malondialdehyde (MDA) content. Exposure at a range of PHE doses (0, 2, 5, 10, and 20 mg kg^-1) for 15 d resulted in the following observations: (1) Compared with urease, as well as acid and alkaline phosphatase activities, cellulase activities in both soil and casts were sensitive to PHE, and could potentially act as biomarkers to provide early-warning signals for soil pollution. (2) Microbial biomass carbon in casts was modified, but with no clear pattern. (3) Cellulase and POD activities, as well as MDA content in earthworms, increased with elevated exposure to PHE in soil. Protease, SOD, and CAT activities exhibited a biphasic dose response to PHE, while acid and alkaline phosphatase activities were inhibited under treatment conditions. (4) Correlation analysis suggested that microbial biomass carbon in casts significantly and positively correlated with cellulase and acid phosphatase activities of earthworms, but negatively correlated with protease activities. A significant but weak negative correlation between alkaline phosphatase activities in casts and POD activities was also observed. Based on these results, we concluded that PHE content in soil modified some biological properties of casts, by partially affecting the earthworm's digestive and antioxidant systems. This study advances our knowledge of earthworm ecology in polluted soil by providing a better understanding of their ecological functions.

Genome-wide identification and expression analysis of the superoxide dismutase (SOD) gene family in Salvia miltiorrhiza

Adverse environmental conditions, such as salinity, cold, drought, heavy metals, and pathogens affect the yield and quality of Salvia miltiorrhiza, a well-known medicinal plant used for the treatment of cardiovascular and cerebrovascular diseases. Superoxide dismutase (SOD), a key enzyme of antioxidant system in plants, plays a vital role in protecting plants against various biotic and abiotic stresses via scavenging the reactive oxygen species produced by organisms. However, little is known about the SOD gene family in S. miltiorrhiza. In this study, eight SOD genes, including three Cu/Zn-SODs, two Fe-SODs and three Mn-SODs, were identified in the S. miltiorrhiza genome. Their gene structures, promoters, protein features, phylogenetic relationships, and expression profiles were comprehensively investigated. Gene structure analysis implied that most SmSODs have different introns/exons distrbution patterns. Many cis-elements related to different stress responses or plant hormones were found in the promoter of each SmSOD. Expression profile analysis indicated that SmSODs exhibited diverse responses to cold, salt, drought, heavy metal, and plant hormones. Additionally, 31 types of TFs regulating SmSODs were predicted and analyzed. These findings provided valuable information for further researches on the functions and applications of SmSODs in S. miltiorrhiza growth and adaptation to stress.

A second intracellular copper/zinc superoxide dismutase and a manganese superoxide dismutase in Oxya chinensis: Molecular and biochemical characteristics and roles in chlorpyrifos stress

A second intracellular copper/zinc superoxide dismutase (icCuZnSOD2) and manganese SOD (MnSOD) were cloned and characterized in Oxya chinensis. The open reading frame (ORF) of OcicCuZnSOD2 and OcMnSOD are 462 and 672 bp encoding 153 and 223 amino acids, respectively. OcicCuZnSOD2 contains two signature sequences, one potential N-glycosylation site, and seven copper/zinc binding sites. OcMnSOD includes a mitochondria targeting sequence of 7 amino acids at N-terminal, one signature sequence, two N-glycosylation sites, and four manganese binding sites. The secondary structure and homology model of OcicCuZnSOD2 include nine β sheets, two Greek-key motifs, and one electrostatic loop. OcMnSOD contains nine α-helices and three β-sheets. Phylogenetic analysis shows that OcMnSOD is evolutionarily conserved while OcicCuZnSOD2 may be gene duplication and is paralogous to OcicCuZnSOD1. OcMnSOD expressed widely in all tissues and developmental stages. OcicCuZnSOD2 showed testis-specific expression and expressed highest in the 5th-instar nymph and the adult. The optimum temperatures and pH values of the recombinant OcicCuZnSOD2 and OcMnSOD were 40 °C and 8.0. They were stable at 25-55 °C and at pH 5.0-12.0 and pH 6.0-12.0, respectively. The activity and mRNA expression of each OcSOD were assayed after chlorpyrifos treatments. Total SOD and CuZnSOD activities first increased then declined under chlorpyrifos stress. Chlorpyrifos induced the mRNA expression and activity of OcMnSOD as a dose-dependent manner and inhibited OcicCuZnSOD2 transcription. The role of each OcSOD gene in chlorpyrifos stress was investigated using RNAi and disc diffusion assay with Escherichia coli overexpressing OcSOD proteins. Silencing of OcMnSOD significantly increased ROS content in chlorpyrifos-exposed grasshoppers. Disc diffusion assay showed that the plates with E. coli overexpressing OcMnSOD had the smaller inhibition zones around the chlorpyrifos-soaked filter discs. These results implied that OcMnSOD played a significant role in defense chlorpyrifos-induced oxidative stress.

Development of novel small molecules for the treatment of ALS

Amyotrophic lateral sclerosis (ALS) is a rare and progressive neurodegenerative disease with unknown etiology. It is caused by the degeneration of motor neurons responsible for controlling voluntary muscles. It has been reported that mutations in the superoxide dismutase (SOD) 1 gene can lead to ALS. SOD1 abnormalities have been identified in both familial, as well as sporadic ALS cases. SOD2 is a highly inducible SOD that works in conjunction with SOD1. SOD2 can be induced through activation of NF-κBs. We previously reported that the novel small molecule, SRI-22818, increases NF-κB expression and activation and SOD2 levels in vitro and has activity in vivo in the SOD1-G93A reference model of ALS. We report herein the synthesis and biological evaluation of SRI-22818 analogs.

Protective effects of Lactobacillus plantarum against chronic alcohol-induced liver injury in the murine model

Long-term alcohol consumption causes liver injuries such as alcoholic hepatitis, fatty liver, and endotoxemia. Some probiotics were demonstrated to exert beneficial effects in the gastrointestinal tract. The present study was aimed to evaluate the protective effects of Lactobacillus plantarum CMU995 against alcohol-induced liver injury. The mice were orally administered L. plantarum CMU995 for 1 week, followed by the administration of alcohol and different tested substances daily for 6 weeks. The liver injury was examined by measuring the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), malondialdehyde (MDA), anti-oxidative enzyme, endotoxin, inflammatory cytokines, and lipid accumulation in the liver or serum among different groups. L. plantarum CMU995 exhibited beneficial effects on alcohol-induced liver injury via reduction in the serum concentration of AST, ALT, cholesterol, triglycerides, endotoxin, TNF-α, IL-1β, and oxidative stress. Furthermore, we also found that the levels of glutathione (GSH), superoxide dismutase (SOD), and intestinal tight junction protein zonula occludens-1 (ZO-1) were considerably higher in L. plantarum CMU995-fed groups when compared with placebo group. Meanwhile, the protective effects were demonstrated biological gradients as controversial dose-dependent. We speculate that L. plantarum CMU995 inhibited the migration of alcohol-derived endotoxin into the blood and liver, thereby improving the intestinal barrier. The present evidence may provide a novel microbiota-based strategy to prevent the alcohol-induced liver injury.

A superoxide dismutase (MnSOD) with identification and functional characterization from the freshwater mussel Cristaria plicata

Manganese superoxide dismutase (MnSOD) is a sort of important metalloenzyme that can catalyze ROS in the organisms. In this study, MnSOD cDNA of C. plicata, designated as CpMnSOD (accession no. MK465057), was cloned from hemocytes. The full-length cDNA of MnSOD was 1096 bp with a 672 bp open reading frame encoding 223 amino acids. The deduced amino acid sequence contained a mitochondrial-targeting sequence (MTS) of 18 amino acids in the N-terminus, and four conserved amino acids for manganese binding (H⁴⁹, H⁹⁷, D¹⁸², H¹⁸⁶). CpMnSOD showed a high level (65-73%) of sequence similarity to MnSODs from other species. The results of Real-time quantitative PCR revealed that CpMnSOD mRNA constitutively expressed in tissues. The highest expression level was in hepatopancreas, followed by muscle, mantle and gill, and the lowest expression level was in hemocytes. After microcystin challenge, the expression levels of CpMnSOD mRNA were up-regulated in hemocytes and hepatopancreas. The cDNA of CpMnSOD was cloned into the plasmid pColdI-ZZ, and the recombinant protein was expressed in Escherichia coli BL21 (DE3). The enzyme stability assay showed that the purified CpMnSOD protein maintained more than 80% enzyme activity at temperature up to 70 °C, at pH 2.0-10.0, and resistant to 8 mol/L urea or 8% SDS.

The effect of reactive oxygen species (ROS) and ROS-scavenging enzymes, superoxide dismutase and catalase, on the thermotolerant ability of Corynebacterium glutamicum

The function of two reactive oxygen species (ROS) scavenging enzymes, superoxide dismutase (SOD) and catalase, on the thermotolerant ability of Corynebacterium glutamicum was investigated. In this study, the elevation of the growth temperature was shown to lead an increased intracellular ROS for two strains of Corynebacterium glutamicum, the wild-type (KY9002) and the temperature-sensitive mutant (KY9714). In order to examine the effects of ROS-scavenging enzymes on cell growth, either the SOD or the catalase gene was disrupted or overexpressed in KY9002 and KY9714. In the case of the KY9714 strain, it was shown that the disruption of SOD and catalase disturbs cell growth, while the over-productions of both the enzymes enhances cell growth with a growth temperature of 30 °C and 33 °C. Whereas, in the relatively thermotolerant KY9002 strain, the disruption of both enzymes exhibited growth defects more intensively at higher growth temperatures (37 °C or 39 °C), while the overexpression of at least SOD enhanced the cell growth at higher temperatures. Based on the correlation between the cell growth and ROS level, it was suggested that impairment of cell growth in SOD or catalase-disrupted strains could be a result of an increased ROS level. In contrast, the improvement in cell growth for strains with overexpressed SOD or catalase resulted from a decrease in the ROS level, especially at higher growth temperatures. Thus, SOD and catalase might play a crucial role in the thermotolerant ability of C. glutamicum by reducing ROS-induced temperature stress from higher growth temperatures.

CuZnSOD and MnSOD from freshwater planarian Dugesia japonica: cDNA cloning, mRNA expression and enzyme activity in response to environmental pollutants

As an important antioxidant enzyme, the superoxide dismutase (SOD) can protect aerobic organisms from oxidative damage through catalyzing the dismutation of superoxide into hydrogen peroxide and oxygen. The SODs have been cloned in some species and their dynamic expression or enzymatic activity in response to environmental stressors were investigated. In the current study, the full-length cDNA of two SODs from freshwater planarian Dugesia japonica were firstly cloned (named as DjCuZnSOD and DjMnSOD, respectively). The complete cDNA of DjCuZnSOD consists of 661 nucleotides encoding 186 amino acids while the 765 bp DjMnSOD encodes a polypeptide of 226 residues. Sequence analysis and multiple alignment showed that DjCuZnSOD possesses two CuZnSOD family signature motifs and an N-terminal signal peptide suggesting it is an extracellular secretory protein. DjMnSOD possesses the MnSOD family signature sequence and is predicted to be located in mitochondrion with a mitochondrial targeting sequence. Phylogenetic analysis based on CuZnSOD and MnSOD orthologs from representative species further verified that DjCuZnSOD is an extracellular CuZnSOD while DjMnSOD is a mitochondrial MnSOD. For the purpose of studying their potential role against environmental pollutants, D. japonica were exposed to glyphosate or 1-decyl-3-methylimidazolium bromide ([C₁₀mim]Br), and the mRNA expression levels of DjCuZnSOD and DjMnSOD along with total SOD activity were measured. The results showed that DjCuZnSOD exhibited more sensitive expression profiles in response to environmental pollutants in contrast with DjMnSOD, and the total SOD activity in response to both pollutants was more related to the expression level of DjCuZnSOD than to DjMnSOD, indicating that the mRNA expression of CuZnSOD would be a more sensitive biomarker than MnSOD in monitoring the pollution of aquatic environment and CuZnSOD might play more important role than MnSOD in eliminating superoxide anions caused by pollutants in D. japonica.

Genome-wide identification, characterization, and expression analysis of superoxide dismutase (SOD) genes in foxtail millet (Setaria italica L.)

Superoxide dismutases (SODs) play important roles in plant growth, development, and response to abiotic stresses. Despite SOD gene families have been identified in various plant species, little is known in foxtail millet (Setaria italica L.). In this study, a systematic analysis of SOD gene family was performed in foxtail millet and the expression pattern of SOD genes in response to abiotic stressors was analyzed at the whole-genomic level. Eight SOD genes were identified in foxtail millet, including 4 Cu/ZnSODs, 3 FeSODs, and 1 MnSOD. These SiSODs are unevenly distributed across 5 of the 9 chromosomes. Phylogenetic analysis showed that SOD proteins could be divided into two major categories (Cu/ZnSODs and Fe-MnSODs), containing seven subgroups, from foxtail millet and other plant species. SOD genes have conserved motif and exon/intron composition in the same subgroup among Setaria italica, Setaria viridis, and Oryza sativa. Additionally, many cis-elements that respond to different stressors were distributed at different densities in the promoters of 8 SiSODs. The expression patterns of SiSODs in different tissues and different abiotic stressors indicated that the SiSODs may play important roles in reactive oxygen species scavenging, caused by various stressors in foxtail millet. This study provides a foundation for the further cloning and functional verification of the SOD gene family response to environmental stimuli in foxtail millet.

Phototoxic effects of PAH and UVA exposure on molecular responses and developmental success in coral larvae

Exposure to polycyclic aromatic carbons (PAHs) poses a growing risk to coral reefs due to increasing shipping and petroleum extraction in tropical waters. Damaging effects of specific PAHs can be further enhanced by the presence of ultraviolet radiation, known as phototoxicity. We tested phototoxic effects of the PAHs anthracene and phenanthrene on larvae of the scleractinian coral Acropora tenuis in the presence and absence of UVA (320-400 nm). Activity of superoxide dismutase (SOD) enzyme was reduced by anthracene while phenanthrene and UVA exposure did not have any effect. Gene expression of MnSod remained constant across all treatments. The genes Catalase, Hsp70 and Hsp90 showed increased expression levels in larvae exposed to anthracene, but not phenanthrene. Gene expression of p53 was upregulated in the presence of UVA, but downregulated when exposed to PAHs. The influence on stress-related biochemical pathways and gene expresson in A. tenuis larvae was considerably greater for anthracene than phenanthrene, and UVA-induced phototoxicity was only evident for anthracene. The combined effects of UVA and PAH exposure on larval survival and metamorphosis paralleled the sub-lethal stress responses, clearly highlighting the interaction of UVA on anthracene toxicity and ultimately the coral's development.

N-acetylcysteine protects against chorioretinal damage induced by photodynamic therapy for experimental choroidal neovascularization in a rat model

PURPOSE

We explored the protective effects of N-acetylcysteine (NAC) on chorioretinal damage induced by photodynamic therapy (PDT) in an experimental rat model of choroidal neovascularization (CNV).

METHODS

Experimental CNV was induced by an argon laser in 24 Brown Norway rats 7 days prior to PDT. Commencing 1 day after CNV induction, 0.5 mL of NAC was orally administered daily to the NAC + group (12 rats), and 0.5 mL of normal saline to the NAC- group (12 rats). Diode laser treatment was delivered for 42 s (total energy, 25 J/cm2) to the left eye prior to verteporfin infusion (PDT-) and to the right eye 15-20 min after such infusion (PDT+). Fluorescein angiography was performed just prior to PDT and enucleation to evaluate fluorescein leakage and CNV closure. We compared the CNV thickness, PDT-induced apoptosis [evaluated via terminal dUTP nick-end labeling (TUNEL)], fluorescein angiographic data, and extents of immunohistofluorescent staining for cleaved caspase-3 and superoxide dismutase (SOD) between the two groups.

RESULTS

Fourteen days after diode laser treatment, the CNV closure rate was significantly higher in the PDT-treated than the control group. However, the CNV closure rates did not differ significantly between the NAC- and NAC + groups. The TUNEL activity (a measure of PDT-induced apoptosis) of retinal cells was higher in the NAC-/PDT + than the NAC+/PDT + group at 1, 3, 7, and 14 days. The cleaved caspase-3 and SOD levels were higher in the NAC-/PDT + than the NAC+/PDT + group at 3 and 7 days.

CONCLUSIONS

PDT triggers oxygen radical-induced injury to, and apoptosis in, the retina. NAC may reduce PDT-induced damage to the retina without compromising the therapeutic efficacy of CNV.

Mitochondrial stress and redox failure in steroid-associated osteonecrosis

The purpose of the role of antioxidant enzymes and mitochondria in the developmental mechanism of steroid-associated osteonecrosis in the femur. In the present study Japanese white rabbits (mean weight 3.5kg) were injected into the gluteus with methylprednisolone (MP) 20mg/kg, and killed after 3 days (MP3 group), 5 days (MP5 group), and 14 days (MP14 group) (n=3 each). As a Control group (C group) Japanese white rabbits not administered MP were used. In experiment 1, the expression of the antioxidant enzymes Superoxide dismutade (SOD) and catalase was compared in liver, kidney, heart, humerus, and femur in C group, and the presence/absence of mitochondria transcription factor A (TFAM) expression was determined by Western blotting (WB) and used to evaluate the number of mitochondria and their function. In experiment 2, the presence/absence of necrosis was determined by immunohistochemistry, while changes in the expression of SOD, catalase, and TFAM in the femur after steroid administration were determined by Western blotting (WB). In experiment 1, intense expression of all of SOD, catalase, and TFAM was found in the liver, kidney, and heart as compared to the humerus and femur. In experiment 2, the expression of all of SOD, catalase, and TFAM in MP3 and MP5 groups was decreased on WB as compared with C group, while in MP14 group a tendency to improvement was seen. Accordingly, steroid-associated mitochondrial injury and redox failure are concluded to be important elements implicated in the pathogenesis of osteonecrosis.

Superoxide Dismutase 1 and 2 Gene Polymorphism in Turkish Vitiligo Patients

Vitiligo is an acquired disease of unknown etiology. Several theories have been proposed to understand the pathogenesis. The role of oxidative stress has been getting more important in recent years. One of the primary antioxidant enzymes in vitiligo is the superoxide dismutase (SOD). The aim of this study is to investigate the polymorphisms of the SOD1 and SOD2 in Turkish vitiligo patients. One hundred one vitiligo patients and 99 healthy controls without family history of vitiligo were included into the study. The SOD1 35 A/C and SOD2 A16V (C/T) polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphim (PCR-RFLP). Vitiligo patients and control group of SOD1 35 A/C and SOD2 A16V (C/T) polymorphism allele frequencies were compared by using χ² tests. The distribution of the SOD1 35 AA and AC genotypes were similar in vitiligo patients and control group. When the patient and the control groups were compared for the SOD2 Ala9Val (C/T) polymorphism, a significant difference was determined for the distribution of the genotypes [p = 0.047, odds ratio (OR) = 2.075, 95% confidence interval (95% CI) = 1.008-4.272]. The relative risk for development of vitiligo was found as a 2-fold increase in the TT genotype. The increase of TT homozygosity in the vitiligo cases creates the problem on the transfer of the enzyme to the mitochondria and thus, the SODs antioxidant effect may decrease in vitiligo but the polymorphism was not determined in all patients, so this study needs to be substantiated by other studies containing a higher number of patients.

Overexpression of Mn-superoxide dismutase in Oxya chinensis mediates increased malathion tolerance

Superoxide dismutase (SOD) is the first line of defense against oxidative damage. Malathion is an organophosphate insecticide and can induce the production of reactive oxygen species (ROS) and cause the intracellular oxidative stress. The present study was undertaken to examine the effects of malathion on SODs activity and their transcriptional levels in Oxya chinensis (Thunberg) (Orthoptera: Acrididae). The results showed that total SOD and MnSOD activities increased as a dose-dependent manner while CuZnSOD activity has no significant changes after malathion treatments. Total SOD and MnSOD activities were the highest at the concentration of 0.8 μg μL^-1 malathion treatment and increased significantly about 1.81- and 2.48-fold compared with the control, respectively. Increased mRNA expression of MnSOD, ecCuZnSOD1, and ecCuZnSOD2 were observed after malathion treatments. Moreover, the alteration of MnSOD transcript was similar to the profiles of MnSOD activity. These results suggested that the up-regulation expression of MnSOD transcript led to the increase of MnSOD activity in order to eliminate the excessive ROS caused by malathion. In addition, we evaluated the role of individual SOD gene in malathion stress by using RNAi and recombinant SOD proteins. The results showed that ROS contents increased significantly after the silencing of MnSOD and ecCuZnSOD1 genes. The OD values of the E. coli cells transformed with pET-28a-OcMnSOD plasmid were 1.13-1.31-fold and 1.08-1.33-fold higher than those of cells with pET-28a plasmids under 0.4 and 0.8 μg μL^-1 malathion treatments, respectively. These findings indicated that MnSOD exerted an important role in defense oxidative stress caused by malathion.

New insights into the antioxidant and apoptotic potential of Glycyrrhiza glabra L. during hydrogen peroxide mediated oxidative stress: An in vitro and in silico evaluation

Plant-derived substances (phytochemicals) are well recognized as sources of pharmacologically potent drugs in the treatment of several oxidative stress related disorders. Our study aims to evaluate the antioxidant and apoptotic effects of Glycyrrhiza glabra L. in both cell free and cell culture system. Plant fractions have been prepared with hexane, chloroform, ethyl acetate, methanol and water and their antioxidant properties are reviewed. Potent antioxidant activity has been well established in both in vitro and in silico studies which is believed to be responsible for the anticancerous nature of the plant. Results obtained indicate that methanol fraction of G. glabra L. exhibited maximum scavenging activity against DPPH and nitric oxide free radicals comparable to standard antioxidant L-AA. Administration of methanol fraction also considerably reduced the malondialdehyde produced due to lipid peroxidation in mammalian liver tissues. Moreover, the levels of antioxidant enzymes SOD, CAT, GST, GPx and GR in the oxidative stress induced tissues were refurbished significantly after treatment with plant's methanol fraction. Moreover, methanol fraction was found to be nontoxic to normal human cell line whereas it inhibited cancer cells HeLa and HepG2 considerably. Apoptosis was established by DAPI fluorescent staining and western blot analysis of pro apoptotic protein caspase-8, caspase-3 and anti-apoptotic protein Bcl-2.There is an up regulation in the levels of pro apoptotic caspase-8 and caspase-3 and down regulation of anti-apoptotic Bcl-2. Furthermore, GC-MS analysis of the methanol fraction revealed the presence of many compounds. In silico experiments using Autodock 4.2 tools showed strong affinity of plant compounds towards antioxidant enzymes (proteins) thus validating with the conclusions of antioxidant enzyme assays and establishing a role in cancer pathogenesis.

4'-Chlorodiazepam is neuroprotective against amyloid-beta in organotypic hippocampal cultures

The translocator protein (TSPO) is an outer mitochondrial membrane protein involved in the transport of cholesterol into the mitochondria, which is the first step for the synthesis of steroid hormones, as well as in the regulation of mitochondrial permeability transition pore opening and apoptosis. Studies have shown that the activation of TSPO may promote neuroprotective actions in experimental models of neurodegeneration and brain injury. In a previous study, our group showed that 4'-chlorodiazepam (4'-CD), a TSPO ligand, was neuroprotective against amyloid-beta (Aβ) in SHSY-5Y neuroblastoma cells. The aim of this study was to evaluate if 4'-CD was also neuroprotective against Aβ in organotypic hippocampal cultures and to identify its mechanisms of action. Aβ decreased the cell viability of organotypic hippocampal cultures, while 4'-CD had a neuroprotective effect when administered at 100nM and 1000nM. The neuroprotective effects of 4'-CD against Aβ were associated with an increased expression of superoxide dismutase (SOD). No differences were found in the expression of catalase, glial fibrillary acidic protein, Akt and procaspase-3. In summary, our results show that 4'-CD is neuroprotective against Aβ by a mechanism involving the modulation of SOD protein expression.

Tissue specific effects of feeds supplemented with grape pomace or olive oil mill wastewater on detoxification enzymes in sheep

The aim of the present study was to investigate the effects of livestock feed supplemented with grape pomace (GP) or olive oil mill wastewater (OMW) byproducts on the enzymatic activity and protein expression of antioxidants enzymes, in liver and spleen tissue of sheep. Thus, 36 male sheep of Chios breed were divided into 3 homogeneous groups, control group (n = 12), GP group (n = 12) and OMW group (n = 12), receiving standard or experimental feed. Liver and spleen tissues were collected at 42 and 70 days post-birth. The enzymatic activity of superoxide dismutase (SOD) and glutathione-s-transferase (GST) and also the protein expression of γ-synthase glutamyl custeine (γ-GCS) were determined in these tissues. The results showed GP group exhibited increased enzymatic activity of GST and protein expression of γ-GCS in liver compared to control group. In GP group's spleen, GST activity was increased compared to control but γ-GCS expression was not affected. In OMW group's liver, GST activity was increased and γ-GCS expression was reduced compared to control. In OMW group's spleen, GST activity was increased but GCS expression was not affected. SOD activity was not affected in both tissues either in GP or OMW group.

Relation of antioxidant status at admission and disease severity and outcome in dogs naturally infected with Babesia canis canis

BACKGROUND

Canine babesiosis is caused by species of the Babesia genus and has become an emerging disease worldwide. To the authors' knowledge there are no reports in which antioxidants have been analyzed in different presentations of canine babesiosis or in which the prognostic value of antioxidants has been studied. The aim of this study was to evaluate whether oxidative stress could be related to the severity and outcome of canine babesiosis. For this purpose a profile consisting of four antioxidant biomarkers (superoxide dismutase - SOD, glutathione peroxidase - GPx, catalase, total antioxidant status - TAS) and malondialdehyde - MDA as an oxidant biomarker (previously evaluated, here studied for comparative purposes) were evaluated in dogs with canine babesiosis of different clinical severity and outcomes.

RESULTS

The study was conducted with a sample of 40 dogs suffering from babesiosis (further divided into uncomplicated, one complication and multiple organ dysfunction syndrome - MODS group) and 30 healthy dogs (control group). Additionally, the babesiosis group was divided according to the anaemia into non-anaemic, mildly anaemic, moderately anaemic and severely anaemic dogs. The results of our study showed significantly decreased SOD, catalase and TAS values in diseased dogs compared to controls, while there were no significant differences in GPx between these groups. Dogs that developed MODS showed lower activities of SOD and GPx and higher MDA values compared to dogs with uncomplicated babesiosis as well as with dogs that developed one complication. Superoxide dismutase, catalase and GPx were negatively correlated whereas MDA was positively correlated with the lethal outcome of the disease. Furthermore, this study detected more pronounced decrease in antioxidant biomarkers (SOD, GPx and catalase) in dogs with moderate anaemia compared to those with mild anaemia.

CONCLUSIONS

The results of this study showed changes in biomarkers related to the antioxidant status of dogs naturally infected with B. canis canis. These biomarkers could be used as indicators of disease severity and outcome in dogs suffering from babesiosis.

Extracellular superoxide dismutase is present in secretory vesicles of human neutrophils and released upon stimulation

Extracellular superoxide dismutase (EC-SOD) is an antioxidant enzyme present in the extracellular matrix (ECM), where it provides protection against oxidative degradation of matrix constituents including type I collagen and hyaluronan. The enzyme is known to associate with macrophages and polymorphonuclear leukocytes (neutrophils) and increasing evidence supports a role for EC-SOD in the development of an inflammatory response. Here we show that human EC-SOD is present at the cell surface of isolated neutrophils as well as stored within secretory vesicles. Interestingly, we find that EC-SOD mRNA is absent throughout neutrophil maturation indicating that the protein is synthesized by other cells and subsequently endocytosed by the neutrophil. When secretory vesicles were mobilized by neutrophil stimulation using formyl-methionyl-leucyl-phenylalanine (fMLF) or phorbol 12-myristate 13-acetate (PMA), the protein was released into the extracellular space and found to associate with DNA released from stimulated cells. The functional consequences were evaluated by the use of neutrophils isolated from wild-type and EC-SOD KO mice, and showed that EC-SOD release significantly reduce the level of superoxide in the extracellular space, but does not affect the capacity to generate neutrophil extracellular traps (NETs). Consequently, our data signifies that EC-SOD released from activated neutrophils affects the redox conditions of the extracellular space and may offer protection against highly reactive oxygen species such as hydroxyl radicals otherwise generated as a result of respiratory burst activity of activated neutrophils.

Oxidative and antioxidative responses in the wheat-Azospirillum brasilense interaction

Azospirillum is a plant growth-promoting rhizobacteria (PGPR) able to enhance the growth of wheat. The aim of this study was to test the effect of Azospirillum brasilense cell wall components on superoxide (O2·(-)) production in wheat roots and the effect of oxidative stress on A. brasilense viability. We found that inoculation with A. brasilense reduced O2·(-) levels by approx. 30 % in wheat roots. Inoculation of wheat with papain-treated A. brasilense, a Cys protease, notably increased O2·(-) production in all root tissues, as was observed by the nitro blue tetrazolium (NBT) reduction. However, a 24-h treatment with rhizobacteria lipopolysaccharides (50 and 100 μg/mL) alone did not affect the pattern of O2·(-) production. Analysis of the effect of plant cell wall components on A. brasilense oxidative enzyme activity showed no changes in catalase activity but a decrease in superoxide dismutase activity in response to polygalacturonic acid treatment. Furthermore, A. brasilense growth was only affected by high concentrations of H2O2 or paraquat, but not by sodium nitroprusside. Our results suggest that rhizobacterial cell wall components play an important role in controlling plant cell responses and developing tolerance of A. brasilense to oxidative stress produced by the plant.

The impact of heterologous catalase expression and superoxide dismutase overexpression on enhancing the oxidative resistance in Lactobacillus casei

Two heme-dependent catalase genes were amplified from genomic DNA of Lactobacillus plantarum WCFS1 (KatE1) and Lactobacillus brevis ATCC 367 (KatE2), respectively, and a manganese-containing superoxide dismutase from Lactobacillus casei MCJΔ1 (MnSOD) were cloned into plasmid pELX1, yielding pELX1-KatE1, pELX1-KatE2 and pELX1-MnSOD, then the recombinant plasmids were transferred into L. casei MCJΔ1. The strains of L. casei MCJΔ1/pELX1-KatE1 and L. casei MCJΔ1/pELX1-KatE2 were tolerant at 2 mM H2O2. The survival rates of L. casei MCJΔ1/pELX1-KatE1 and L. casei MCJΔ1/pELX1-KatE2 were 270-fold and 300-fold higher than that of the control strain on a short-term H2O2 exposure, and in aerated condition, the survival cells counts were 146- and 190-fold higher than that of the control strain after 96 h of incubation. Furthermore, L. casei MCJΔ1/pELX1-MnSOD was the best in three recombinants which was superior in the living cell viability during storage when co-storage with Lactobacillus delbrueckii subsp. lactis LBCH-1.

Physiological and biochemical response to drought stress in the leaves of Aegiceras corniculatum and Kandelia obovata

Drought stress is one of the major abiotic stresses that affects plant growth and metabolism adversely around the world. According to this research, the effect of drought stress on the activity of antioxidative enzymes, soluble sugar, protein and lipid peroxidation were studied in leaves of two mangrove plants, Kandelia obovata and Aegiceras corniculatum. The result showed that superoxide dismutase (SOD) and peroxidase (POD) varied significantly between the leaves and roots studied. The activities increased in different stress levels. The production rate of O 2 (-·) changed with the activity of SOD and POD. Lipid peroxidation was enhanced and Glycine betaine (GB) could decrease the level of malonaldehyde in order to reduce the damage of membrane system. The content of soluble sugar and protein also increased under drought stress and GB helped to eliminate the accumulation of them which somehow enhance the ability of defensing the plants under drought stress. These results indicated that antioxidative activity may play an important role in A. corniculatum and K. obovata and that cell membrane in leaves of K. obovata had greater stability than those of A. corniculatum. Exogenous application of GB had positive effects on A. corniculatum and K. obovata under drought stress which could be products exogenously applied to mangrove plants in order to alleviates the adverse effects.

Antioxidative responses of Pseudomonas fluorescens YZ2 to simultaneous exposure of Zn and Cefradine

Binary pollution of both heavy metals and antibiotics has received increasing attentions for their joint effects of eco-toxicity and health hazards. To reveal the effects of mixtures of different pollutants on bacterial antioxidant response system, Pseudomonas fluorescens ZY2, a new strain isolated from swine wastewater, was chosen to determinate growth (bacterial density OD600), reactive oxygen species (ROS) concentration, protein concentration and superoxide dismutase (SOD) activity under exposure treatments of Zn, Cefradine or Zn + Cefradine. Bacterial densities of all the treatment groups increased significantly over the incubation time, but those containing pollutant addition were slightly lower than the control at different times of incubation. Both ROS concentration and SOD activity increased first and then decreased (p < 0.01) over time, which was opposite to the protein concentrations (p < 0.01), showing a much significant increase by Cefradine alone. With Zn concentration increasing from 40 to 160 mg/L, the intracellular SOD activity increased as a response to the improvement of ROS (p < 0.05), while the balance between ROS and SOD was broken down due to the disproportionate change of total SOD activity and ROS concentration, the bacterial densities therefore decreased for the weak resistance. With the combined treatment of Zn (200 mg/L) and Cefradine (1 mg/L), though the toxicity of Zn caused a much significant increase of ROS, the bacterial resistance was further improved showing a more significant increase of total SOD activity and the bacterial densities therefore increased bacterial growth. Zn concentration also affected the protein synthesis. Either single or binary stress induced the bacterial resistance by regulating SOD activity to eliminate ROS. All results of the bacterial oxidant stress, SOD response and protein synthesis in the combined treatment groups were more complicated than those in single treatment groups, which depended on the properties of the single treatment as well as the interaction between the two treatments upon bacterial activity. For P. fluorescens ZY2, the mediation of SOD activity to eliminate ROS in response to the combined exposure to Zn and Cefradine was first revealed as one of the co-resistance mechanisms, which is informative to further understanding the risk of antibiotics resistant bacteria to human and environmental health more accurately.

Iron incorporation into MnSOD A (bacterial Mn-dependent superoxide dismutase) leads to the formation of a peroxidase/catalase implicated in oxidative damage to bacteria

BACKGROUND

Mn/Fe-superoxide dismutase (SOD) is a family of enzymes essential for organisms to be able to cope with oxygen. These enzymes bound to their classical metals catalyze the dismutation of the free radical superoxide anion (O2(-)) to H2O2 and molecular oxygen. E. coli has the manganese-dependent SOD A and the iron-dependent SOD B.

METHODS

Strains of E. coli overexpressing SOD A or SOD B were grown in media with different metal compositions. SODs were purified and their metal content and SOD activity were determined. Those proteins were incubated with H2O2 and assayed for oxidation of Amplex red or o-phenylenediamine, consumption of H2O2, release of iron and protein radical formation. Cell survival was determined in bacteria with MnSOD A or FeSOD A after being challenged with H2O2.

RESULTS

We show for the first time that the bacterial manganese-dependent SOD A when bound to iron (FeSOD A) has peroxidase activity. The in vivo formation of the peroxidase FeSOD A was increased when media had higher levels of iron because of a decreased manganese metal incorporation. In comparison to bacteria with MnSOD A, cells with FeSOD A had a higher loss of viability when exposed to H2O2.

GENERAL SIGNIFICANCE

The biological occurrence of this fundamental antioxidant enzyme in an alternative iron-dependent state represents an important source of free radical formation.

Imbalance in the blood antioxidant system in growth hormone-deficient children before and after 1 year of recombinant growth hormone therapy

The aim of our study was to examine the effects of 12-month therapy with recombinant growth hormone (rGH) on the blood antioxidant system in children with growth hormone deficiency (GHD). Total antioxidant capacity (TAC) of plasma was measured by FRAP (ferric reducing antioxidant power or ferric reducing ability of plasma); activities of superoxide dismutase (SOD) and catalase (CAT) in erythrocytes were assessed; non-protein thiols (NT) and ceruloplasmin (CP) levels were also measured. These parameters were determined before and after 12 month of rGH treatment. Eleven treatment-naive prepubertal children with growth hormone deficiency were included in the study. Another 11 prepubertal children comprised a control group. Before rGH treatment, TAC of plasma and NT level in the control group were significantly lower (726 ± 196 vs. 525 ± 166 µmol/L, P = 0.0182 and 0.92 ± 0.18 vs. 0.70 ± 0.22 µmol/ml, P = 0.0319, before and after the therapy, respectively). The only parameter that significantly (19.6 ± 4.7 vs. 14.5 ± 3.4 Units/g Hb, P = 0.0396) exceeded the same in the control group after rGH therapy was SOD activity. However, none of the measured parameters of antioxidant system in GHD children, except for TAC (525 ± 166 vs. 658 ± 115 µmol/L, P = 0.0205), exhibited significant improvement toward the end of the 12-month treatment period, although non-significant changes in CAT activity and CP level were also observed. This work has demonstrated that some parameters of the blood antioxidant system are out of balance and even impaired in GHD children. A 12-month treatment with rGH resulted in a partial improvement of the antioxidant system.

Identification and analysis of icCu/Zn-SOD, Mn-SOD and ecCu/Zn-SOD in superoxide dismutase multigene family of Pseudosciaena crocea

Superoxide dismutases (SODs) belong to a significant and ubiquitous family of metalloenzymes for eliminating excess reactive oxygen species (ROS). In this paper, the complete open reading frames (ORFs) of intracellular Cu/Zn-SOD (icCu/Zn-SOD), Mn-SOD and extracellular Cu/Zn-SOD (ecCu/Zn-SOD) were identified from the large yellow croaker (Pseudosciaena crocea, designated as LycSOD1, LycSOD2 and LycSOD3). The sequences were 465 bp, 678 bp and 645 bp (GenBank accession no. KJ908287, KJ908285 and KJ908286), encoding 154, 225 and 215 amino acid (aa) residues respectively. The deduced aa sequences of LycSOD1, LycSOD2 and LycSOD3 shared high identity to the known icCu/Zn-SODs, Mn-SODs and ecCu/Zn-SODs with BLASTp and Phylogenetic analysis. Two conserved Cu-/Zn-binding sites (H-44, H-47, H-64, H-121 for Cu binding and H-64, H-72, H-81, D-84 for Zn binding in LycSOD1, H-98, H-100, H-115, H-164 for Cu binding and H-115, H-163, H-166, D-169 for Zn binding in LycSOD3) and one conserved manganese coordinating sites (H-57, H-101, D-186, H-190 in LycSOD2) were identified. The total length of DNA sequences of LycSOD1, LycSOD2 and LycSOD3 were 3447 bp, 3387 bp and 3886 bp respectively, and there were 4 introns and 5 exons in Cu/Zn-SODs (LycSOD1 and LycSOD3), but only 3 exons and 2 introns in LycSOD3. Spatial expression analysis indicated the highest mRNA expression of three SODs all appeared in liver among eight detected tissues, the highest expression level was LycSOD1, then LycSOD2 and the lowest was LycSOD3 for almost each tissue. The expression of LycSOD1, LycSOD2 and LycSOD3 mRNA were all up-regulated in liver after Vibrio alginolyticus stimulation. The temporal expression peak of LycSOD1 and LycSOD2 were around 9-fold and 8-fold compared to control respectively, whereas, LycSOD3 got the highest level at 48 h post-injection (about 4.2-fold). All the results gave several new and useful evidences for further understanding the regulatory mechanism of superoxide dismutases in the innate immune system of sciaenidae fish.

The protective activity of Conyza blinii saponin against acute gastric ulcer induced by ethanol

ETHNOPHARMACOLOGICAL RELEVANCE

Conyza blinii H.Lév., is a type of natural plant. Its dried overground section is used to treat infections and inflammations in traditional Chinese medicine. Triterpenoidal saponins have a wide range of bioactivities, for instance, anti-cancer, anti-virus and anti-anaphylaxis. Conyza blinii saponin (CBS), mainly composed of triterpenoidal saponins, is the total saponin of Conyza blinii H.Lév. It has been reported that CBS also has gastric mucous membrane protection activity. This study aims to test CBS׳s protective activity of gastric׳s mucous membrane against ethanol. This investigation may lead to the development of novel drug from natural products as anti-ulcer agent, or as gastric mucous protective against chemical damage.

MATERIALS AND METHODS

CBS (Conyza blinii saponin) is the total saponin of Conyza blinii H.Lév., which was obtained as described previously. We tested the protective activity of CBS against ethanol-induced ulcer. Thirty six rats were grouped randomly as 'NORMAL', 'CONTROL', 'MODEL', 'LOW DOSE', 'MEDIUM DOSE' and 'HIGH DOSE'. The 'NORMAL' group were rats with no pathological model established within it. The 'CONTROL' group was administrated with colloidal bismuth subcitrate, while 'MODEL' group was not given any active agents apart from absolute ethanol in order to obtain gastric ulcer model. The three 'DOSE' groups were treated with different concentrations of CBS (5, 10, 20mg/mL) before administration followed by absolute ethanol. All rats were sacrificed after the experiment to acquire the gastric tissue. The ulcer index (UI), malondialdehyde (MDA) and superoxide dismutase (SOD) were measured to monitor the activity of CBS. Besides, the rat gastric tissue was made to paraffin section and stained using the Hematoxylin-Eosin (HE) method. The histopathology examination was carried out to examine CBS efficacy in terms of gastric mucous protection.

RESULTS

We found that CBS had a profound protection activity against acute gastric ulcer induced by ethanol and this activity displayed a concentration-dependent manner. The efficacy of 10 and 20mg/mL CBS was comparable with colloidal bismuth subcitrate (P<0.05). All three level of CBS tested were able to significantly reduce UI, MDA and enhance SOD level (P<0.05).

CONCLUSIONS

It was deduced that the mechanism for such activity would be anti-lipid peroxidation, facilitating free radicals clearance. In addition , histopathology examination of the gastric mucous membrane supported the same conclusion, that CBS can efficiently suppress the inflammatory reactions, bleeding and protect the gastric mucosa.

The effects of superoxide dismutase addition to the transport medium on cumulus-oocyte complex apoptosis and IVF outcome in cats (Felis catus)

The aim of the present study was to examine the effects of superoxide dismutase (SOD) addition to the ovary transport medium (4°C, 3-72 h) on ovarian cell viability and apoptosis and in vitro embryo production (IVEP) in domestic cats. The ovaries collected from 76 mixed-breed domestic queens were randomly assigned to the control or SOD-treated groups and incubated for 3, 24, 48 or 72 h. The ovaries were then subjected to the following: (1) fixed in formalin to assess the incidence of apoptosis (fragmented DNA in situ detection kit), (2) stored at -196°C in liquid nitrogen to evaluate the expression of the pro-apoptotic Bax gene and the anti-apoptotic Bcl-2 gene (RT-PCR), and (3) used to obtain the cumulus-oocyte complexes (COCs) in order to test the cell viability (carboxyfluorescein or trypan blue staining) and IVEP. The incidence of apoptosis appeared to be higher in the control compared with the SOD-treated ovaries. The ovarian expression of Bax was lower and the Bcl-2 expression was higher in the SOD-treated group compared with the control group. The presence of SOD in the transport medium increased the viability of COCs and IVEP compared with the control medium. In summary, the supplementation of the ovary transport medium with SOD reduced cellular apoptosis and enhanced COC survival and IVEP in domestic cats.

Three novel superoxide dismutase genes identified in the marine polychaete Perinereis nuntia and their differential responses to single and combined metal exposures

To identify superoxide dismutase (SOD) genes and evaluate their usefulness as potential markers for monitoring metal toxicity in aquatic environment, we cloned, sequenced, and characterized 3 SOD genes (Cu/Zn-SOD1, Cu/Zn-SOD2, and Mn-SOD) from the marine polychaete Perinereis nuntia. The accumulated metal contents and expressions of 3 SOD genes were compared after exposure to single and combinations of heavy metals, As, Ni, and Pb. The deduced amino acid sequences of the 3 SODs had evolutionary conserved domains, such as metal binding sites, and signature sequences. The phylogenetic analysis revealed that Cu/Zn-SOD1, Cu/Zn-SOD2, and Mn-SOD were clustered with extracellular Cu/Zn-SOD, intracellular Cu/Zn-SOD and mitochondrial Mn-SOD, respectively, of other species. The accumulated contents of Ni and Pb increased significantly in a time - dependent manner after exposure to both single and combination of the metals. However, the concentration of As did not change significantly in the exposure test. The quantitative real-time polymerase chain reaction (PCR) array showed that the 3 SOD genes had differential expression patterns depending on the exposure condition. The expression of all SODs mRNAs was significantly elevated in response to Pb alone and in combination with As. The mRNA level of Cu/Zn-SOD1 was the highest after exposure to Pb alone, while that of Mn-SOD was remarkably enhanced after exposure to a combination of As and Pb. Exposure to Ni alone rapidly elevated the expression of Cu/Zn-SOD1 and Mn-SOD mRNA, which then gradually decreased. Exposure to As had no significant effect on the modulation of any of the SOD genes of P. nuntia. These results suggest that all SOD genes might play important roles in cellular protection as antioxidant enzymes against heavy metal toxicity via different modes of action in P. nuntia and might have the potential to act as indicators in an environment containing a mixture of metals.

Effect of a polybrominated diphenyl ether congener (BDE-47) on growth and antioxidative enzymes of two mangrove plant species, Kandelia obovata and Avicennia marina, in South China

The effects of BDE-47 on the growth and antioxidative responses of the seedlings of Kandelia obovata (Ko) and Avicennia marina (Am) were compared in an 8-week hydroponic culture spiked with different levels of BDE-47, 0.1, 1, 5 and 10 mg l(-1). The two highest BDE-47 levels significantly suppressed the growth and increased the activities of three antioxidative enzymes, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), of Ko in week 1. However, SOD and POD activities at high levels of BDE-47 became lower than the control in week 8. On the contrary, growth of Am was not affected at all contamination levels, and the activities of three enzymes were enhanced by BDE-47 in weeks 1 and 4, but such stimulatory effect became insignificant in week 8. Avicennia was more tolerant to BDE-47 toxicity than Kandelia, as its antioxidative enzymes could better counter-balance the oxidative stress caused by BDE-47.

Potential reproductive health effects and oxidative stress associated with exposure to potassium dichromate (K2Cr2O7) and magnesium sulphate (MgSO4) in male mice

OBJECTIVE

To investigate the potential harmful effects of potassium dichromate and magnesium sulphate causing oxidative stress and reproductive toxicity in adult male mice model.

METHODS

The experimental work was conducted on sixty male mice (Mus musculus) divided into three groups. Mice in group B and C received potassium dichromate and magnesium sulphate of 5.0 and 500 mg/Kg body weight/ml respectively, for sixty days. The blood sample was analyzed to assess oxidative stress and cellular damage.

RESULTS

RESULTS showed high malondialdehyde (MDA) and low levels of antioxidant enzymes [catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx)] in both potassium dichromate and magnesium sulphate administrated groups as compared to control group. Reduced number of sperm count and excessive destruction of testicular follicles, including destruction of spermatids, leydig cells and sertoli cells, were also seen in both groups.

CONCLUSION

We concluded from present study that potassium dichromate and magnesium sulphate causes oxidative stress by generation of reactive oxygen species (ROS) and causing DNA damage in testicular cells leading to adverse reproductive abnormalities.

Assessment of oxidative stress and inflammatory process in patients of multiple myeloma

Multiple myeloma is a disseminated malignancy of monoclonal plasma cells that accounts for 15 % of all hematological cancers. The present study was conducted to evaluate the role of inflammation and oxidant-antioxidant dynamics in the etiology of this disease. The study population comprised of 20 cases of multiple myeloma and 20 healthy controls. The parameters evaluated were serum malondialdehyde (MDA), superoxide dismutase (SOD) and ferritin levels. The serum MDA levels were 1.9 ± 0.96 nmol/ml in cases as compared to 0.98 ± 0.55 nmol/ml in the controls. Similarly, a statistically significant difference was noted in the SOD and ferritin levels between the cases and controls (93.2 ± 23.8 vs. 210.1 ± 190.5 U/ml and 285.8 ± 216.4 vs. 131.8 ± 30.1 ng/ml respectively). Our study highlights the imbalance in the oxidant-anti oxidant mechanism and the role of smoldering inflammation in the etiology of multiple myeloma.

Studies on the effect of monosodium glutamate (MSG) administration on the activity of xanthine oxidase, superoxide dismutase and catalase in hepatic tissue of adult male mice

Subcutaneous administration of monosodium glutamate (MSG), to normal adult male mice, for six consecutive days at dose levels of 4 and 8 mg/g body weight, significantly increased the level of free radical initiating enzyme, xanthine oxidase, whereas the activity of free radical scavenging enzymes, like catalase and superoxide dismutase was significantly decreased in hepatic tissue. These observations suggested that ingestion of MSG at dose level of 4 mg/g body weight and above, induced oxidative stress in the hepatic tissue of adult male mice.